Wenner four-pin method

Buried pipelines are subject to external corrosion from ground water and highly conductive soils. The corrosiveness of soils is often estimated based on soil resistivity measurement. The measurement is made with the Wenner four-pin method, which is used in conjunction with a Vibroground(1 and a Miller U 10-pin conductor set to determine the average electrical resistivities. A general relationship between corrosion and soil resistivity is as follows ... 

Fig. 15.8 Wenner four-pin method for measuring soii resistance.

This method is based on the same principle as the Wenner four-pin test method. There are four points of electrical contact with the soil the current is driven through the two... 

Soil resistivity can be measured by the so-called Wenner four-pin technique or, more recently, by electromagnetic measurements. The latter allows measurements in a convenient manner and at different soil depths. Another option for soil resistivity measurements is the so-called soil box method, whereby a sample is taken during excavation. Preferably sampling will be in the immediate vicinity of a buried structure (a pipe trench, for example). 

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